The searing heat wave put normal life out of gear in most parts of north India, Telangana and Andhra Pradesh.

Mankind suffered a lot at Khammam in Telangana which at 48 degree Celsius made outing a difficult task as everyone stayed in doors for most part of the day on Sunday. The searing heat wave that swept large parts of India killed at least 500 people in the last two days.

While Khammam scored the maximum, Allahabad was the second hottest at 47.7°C, six degrees above normal; Nandigama in Andhra Pradesh was a notch under as it sizzled at 47°C while Odisha’s Angul district tipped the scales at 46.7°C. However, Delhi was a shade better at 43.5°C on Sunday.

In a release, the Centre for Holistic Development, an NGO in Delhi, said the heat wave had claimed the lives of 186 people till Saturday, 80% of them homeless. There is no official data in the capital on the number of deaths because of heat wave till now.

The sunstroke and heat-related ailments claimed over 400 deaths in Andhra and Telangana alone, say official sources. “We have recorded 246 deaths from Wednesday till Sunday. Prakasam and Visakhapatnam districts are the worst affected with 57 and 53 deaths respectively,” said Dhanunjaya Reddy, director, Andhra disaster management department.

The Telangana government has put the toll at 188 — from April 15 till Sunday — but most of the deaths were reported over the past few days because of unusually high temperatures.

Andhra chief minister Chandrababu Naidu has advised people to take remedial measures when out in the sun. His government announced Rs 1 lakh to the families of heat wave victims.

“The conditions continuing since Wednesday is the result of a northwesterly dry wind blowing from Rajasthan and Gujarat and a surface trough running from Odisha to Tamil Nadu along the coast of Andhra. Cloudless skies allowing penetration of the sun rays which are absorbed by the land, adding to the heat,” said Y.K. Reddy, director in-charge, meteorological centre, Hyderabad.

Many parts of Rajasthan, Madhya Pradesh, Maharashtra, West Bengal, Uttar Pradesh, Chhattisgarh and Karnataka are also reeling under the summer scorcher. In Rajasthan, the mercury touched 46.5°C in Jaisalmer and Kota was close behind at 45.4°C.

In West Bengal, oppressive humidity couple with the heat killed a factory worker. Sheikh Rustam, 45, was working in an open area inside a steel factory in Burdwan when he complained of exhaustion and died at a nearby hospital.

The mercury is set to further rise in all major cities of Uttar Pradesh that saw a big jump in day temperature even as the weather office cautioned public on the heat wave.

Medical experts said long exposure to extreme heat raises human body temperature to such levels that protein cells start to “boil like egg whites”, a case of internal combustion that eventually shuts down the brain.

Hospitals have been flooded with cases of heatstroke in Gurgaon and Delhi. “Prolonged sun exposure dehydrates the body and its ability to control heat. So, we advise people to be extra cautious in the summer months,” said Satish Koul, general physician at Columbia Asia Hospital, Gurgaon.

Tummy upsets, headache, fever, rashes and skin allergies from sunburn are other less severe symptoms.

“Drink plenty of water, avoid the sun and never go out on an empty stomach,” reads the general advisory.